on macOS (I'm on 10.14.6) when my Graph tab is on a separate window outside the main Unity Editor, as soon as I create a new node, the Unity editor hangs with a spinning pinwheel forever.
Pausing and looking at the callstacks within Visual Studio when in that state, it seems to be searching for the Unity main window forever. The workaround is to have the Graph tab always attached within the Unity main view.
The problem does not occur on Windows.
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